Boat hull



Sept. 8, 1931. E. B. CARNS 1,822,199

, BOAT HULL Filed May 20, 1927 Patented Sept. 8, 1931 UNITED STATES PATENT OFFICE EDMUND B. GARNS, OF NEW YORK, N. Y., ASSIGNOR TO CAIRNS DEVELOPMENT COMPANY, Y.

013 WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE BOAT HULL Application filed May 20,

My invention relates to improvements in boat hulls, and the object of my invention is to produce a hull which can be made cheaply, of a most attractive design, of light weight, and enormous strength. 7

My invention is particularly adapted to the production of speed boats and relatively small vessels, although the principle can be carried out in larger structures, if so desired.

For boats up to a certain size, it is possible to make the plates comprising the several sides of the hull, each of a single piece, rolled or shaped to the desired compound curvature, and when these are assembled and internally braced, according to my invention, the structure is very light and strong.

My invention is, also, particularly intended to produce a structure in which the various parts can be made in duplicate and then, conveniently and economically assembled so as to put the building .of such boats of a good commercial, productive basis.

The invention is further intended to produce a hull having the several plates forming its shell of such a shape as to conduce to speed, strength and beauty.

These, and other advantages of the invention, will appear more clearly from the description which follows.

Reference is to be had to the accompanying drawings in which similar reference characters represent the corresponding parts in all views.

Figure 1 is a cross section, partly in cross section, and partly in perspective of my improved hul Figure 2 is an enlarged sectional detail showing the keel portion of the hull.

Figure 3 is a plan view of a hull showing my improvement.

Figure 4 is a side elevation thereof.

Figure 5 is a broken longitudinal section of the after part o'f'the vessel, and

Figure 6 is a diagram representing nossible compound curves of one of the hull plates.

I have shown my invention as applied to making speed boats such as are provided on the after part with steps towards the aft 1927. Serial No. 192,880.

part of the boat, the hull being reduced at making of this type of boat, but it is not confined to the hull having such steps.

As shown in the drawing, the hull 10 is made of the similar bottom sheets 11 which lie on each side of the'keel and which are preferably slightly inwardly curved in cross section, the side plates 12 of similar curvature, and the top plate 13 which takes the place of the ordinary deck.

For boats up to a certain size, I have found it feasible to shape these several sheets to desired compound curvature so that they will have the transverse section de sired and will taper toward the ends.

A sheet having a compound curvature such as described, can be made according to the method and apparatus disclosed inmy applications for Letters Patent of the United States, Serial No. 174,454, filed Mar. 11, 1927 entitled Art of shaping curved sheets, and Serial No. 357,036, filed April 22, 1929, entitled Metal forming machine. By reference to said applications, it will be seen that a sheet is simultaneously shaped with desired longitudinal and transverse curvature forming a single compound curved surface which is exceptionally stiff. This will also be understood by reference to Figure 6 of the drawings, in which the line a represents the transverse curvatu-reof a sheet, forexample 12, and in which the center a is located on the outer side of the sheet 12.

The line b will represent the longitudinal "curvature but as the sheet '13 is crowning,

the center of the transverse curvature in this case would be'inside the sheet. In any event, the simultaneous transverse shaping of the sheet and also drawing it to the longitudinal curvature desired produces simultaneously this combination of curvatures forming a compound curvature and a sheet thus formed is unusually strong and capa ble of offering unusual resistance because this simultaneous shaping to the compound curvature described leaves the metal under tension and therefore gives to the sheet its exceptional stiffness, as is well understood in the art. When sheets are thus shaped they can, because of these peculiar characteristics, be joined together to make a boat hull, for example, which will need but little if any transverse bracing and thus a simple structure of great strength and unusual internal clearness can be produced, as more particularly described below.

These several sheets 11, 12 and 13 meet edge to edge and can be united at the meeting edges in any usual or preferred way but they are reinforced, as hereinafter described, at such meeting points.

I have shown the hull provided with a cock pit 1% which is conventionally shown, and with steps or inset parts 15 and 16. There can be any desired number of these steps.

I have also shown the hull provided with a keel channel 17 in the form of a conventional channel iron which is placed open side down as in Figure 2 and is adapted to contain the keel 18 which can be of any approved type. This arrangement of the keel piece 17 serves for the convenient in sertion and fastening of the keel and also serves to brace the under part of the hull at a point where it must be strongest.

The sheets 11. where they ioin the keel piece. are flanged at 11 and firmly riveted or otherwise fastened to the keel piece and keel, thereby making a simple but strong connection which serves to securely brace the hull.

The hull is provided wih members 19 in the form of conventional Ts which, instead of running transversely, according to conventional practise, run lengthwise of the hull, and similar members 19 are arranged at the top just below the deck or cover sheet 13.

The sheets 11 and 13 are firmly secured to the members 19 and 19. and itwill be noticed by reference to Figure 1 that two of the under members are placed at the junctions of the plates 11 and 12 so as to brace these points securely.

The upper and lower members 19 and 19' are trussed on the cantilever principle and the struts 21 of the trusses are preferably thicker in the center and taper toward the ends, thus making the struts strong, but dispensing with unnecessary weight.

here adjacent struts meet. they preferably abut as shown. thus making a particularly strong connection. The struts are also preferably arranged in pairs as shownv in Figure 2, which facilitate their attachment to the ribs and, in this connection, I wish to call attention to the fact that a rib 19 can be placed directly upon the keel piece 17, thus making a particularly rigid keel construction.

The upper and lower members 19, 19 are also connected by braces 22 which can conveniently and effectively be tubular, and these braces are arranged diagonally as shown in Figure 1; thus, a brace 22 will extend from one of the members 19 or 19, diagonally across to another member which is not in vertical alignment with the first member so that the effect is to brace the hull transversely as well as vertically.

At the junction of the sheets 12 and 13, I place longrons 20 which extend the full length of the hull and which are tubular as shown, and also essentially triangular, each longer-on having two faces which are shaped to nicely fit the plates 12 and 13, as the drawing shows, so as to make a firm connection l etween the parts, and a very strong bracing.

The steps 15 and 16 are not new in hull constructions, but I make them in what I believe to be a novel way which simplifies and strengthens this type of construction. At points where the steps occur, the bottom sheets 11 are cut and the after sheets moved inward as shown to reduce the hull section and make the steps. At such points, I use transverse bulkheads 23 which can be cut away in the center for lightness and to provide for access to the hull and these bulkheads each fit the larger hull section and have flanges 24 which are riveted or otherwise fastened to all the hull plates. While these bulkheads may be placed in other parts of the hull, they are essential at each step and at such points it will be seen that the bulkhead 23 which fills the larger hull section closes, as shown at 25, the gap which would otherwise occur between the larger and small hull sections. At such points, I use an angle connecting brace 24 which is shaped to fit against the bottom sheets 11 of the smaller hull section and one flange of this brace is riveted to the sheet 11 and the other flange to the adjacent bulkhead 23. Thus I make a very strong connection between the parts and the tight closure of the step gaps.

It will be also understood that the sheets ll may be uncut and crimped in at these points without breaking, and the sheets are preferably formed with these crimps or steps at the time they are curved and at the same operation. It will be further noticed that it is a simple matter to put a gasket or caulking material between the bulkheads and braces 24 if desired.

From the foregoing description, it will be apparent that this hull can be made with the sheets 11, 12 and 13 of the desired longitudinal and transverse curvature so as to be assembled in the form shown to make a cheap, strong, handsome hull, and their shape is such that, when united edge to edge, each effectually braces the other, and this, taken in connection with the members 19, 19', longrons and internal braces, makes a cheap structure which is light and enormously strong.

It will be also understood that while I have shown a structure particularly adapted to the building of small boats, and especial- 1y speed boats, the principle can be carried out in large vessels, in which case, the corresponding sheets 11, 12 and 13 will, of course, be made up in sections to avoid impractical lengths.

It will also be understood that the shape of the several sheets can be departed from and that a hull can be made up on the lines described with a greater or less number of sheets without affecting the invention.

I claim:

1. A metal boat hull having top, bottom and sides formed of preformed sheets shaped to compound curvature, longitudinal members at the top and bottom parts of the hull, and longrons fitting against the top and side sheets at the junction of said sheets.

2. A metal boat hull having an internal frame, and preformed covering sheets of compound curvature united at bow and stern and fastened only to members of the frame running fore and aft.

3. A metal boat hull having an internal frame, steps, transverse bulkheads at the steps, and preformed covering sheets of compound curvature united at how and stern, said sheets being fastened to the bulkheads and at other parts to only those members of the frame which run fore and aft.

4. A metal boat hull having an internal frame, steps, transverse bulkheads forming part of the steps, and preformed covering sheets of compound curvature united at how and stern said sheets being fastened to the bulkheads and at other points to only those members of the frame which run fore and aft.

5. A metal boat hull having top, bottom- 7 A metal boat hull having its enclosing shell formed of preformed sheets each having continuous curves longitudinally and continuous curves transversely and internal fore and aft rows of bracing for the hull.

8. A metal boat hull having a shell formed of preformed compound sheets each having continuous curves longitudinally and continuous curves transversely, whereby each sheet is longitudinally and transversely arched, and internal bracing members fastened to said sheets and running in rows extending fore and aft of the hull. V 9. A metal boat hull having distinct bottom top and sides each made of preformed sheets of compound curvature, whereby each sheet is continuously curved longitudinally and continuously curved transversely, each sheet forming a section of a compound curved shell.

10. A metal boat hull having a shell formed of preformed compound curved sheets, each having continuous curves longitudinally and continuous curves transversely, whereby each sheet is longitudinally and transversely arched, inner bracing members fastened to said sheets and steps in the bottom portion of said hull.

In testimony whereof, I have signed my name to this specification this 16th day of May, 1927.

EDMUND B. CARNS. 

